I propose a "Conformance Applicability Notes" area that would go at the top of the guidelines, as in ATAG 2.0 (http://www.w3.org/WAI/AU/2011/ED-ATAG20-20111028/Overview.html#part_a_applic_notes)....
Proposed wording:
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1. Dynamic Content: Success criteria that require user agents to maintain a content history (e.g., maintaining a viewport history) do not apply in the case of content that is changing dynamically.
2. Unrecognizable Content: Success criteria that require user agents to process content according to the recognized semantics of the content (e.g. is an image, is a button, etc.) do not apply in the case of content in which the semantics are not present (e.g., scripted content lacking WAI-ARIA information).